中中新世以来阿尔金断裂走滑未造成柴达木盆地整体旋转

发布时间：2019-02-18 15:36

【摘要】：通过柴达木盆地南八仙剖面磁性地层学研究,建立了部分上油砂山组磁极性序列,认为该剖面时代为7.5~9.0 Ma。从320块样品的古地磁数据分析,揭示了一组高温特征剩磁分量,在95%置信度下通过倒转检验(B级),说明这组高温分量很可能代表岩石形成时的原生剩磁,其特征剩磁方向为:地理坐标下为Dg=358.5°,Ig=40.5°,k=28.5,α95=4.2,层面坐标下为Ds=1.0°,Is=41.5°,k=34.0,α95=3.8;相应的极位置为λp=75.9°N,φp=270.5°E,dp=2.8°,dm=4.6°。通过与同时代柴达木盆地及邻区的古地磁极对比,说明中中新世以来柴达木地块整体上没有经历明显旋转运动,阿尔金断裂活动致使肃北等毗邻断裂带地区发生了构造旋转。
[Abstract]:Based on the study of magnetic stratigraphy in the Nanbaxian section of Qaidam Basin, the magnetic polar sequence of part of the Upper Yeshaishan formation has been established, and the age of the section is considered to be 7.5? 9. 0 Ma.. From the analysis of the paleomagnetic data of 320 samples, a group of high temperature characteristic remanent magnetic components are revealed. The inversion test (B level) at 95% confidence indicates that this group of high temperature components is likely to represent the primary remanence of rock formation. The direction of remanent magnetization is: Dg=358.5 掳, Ig=40.5 掳, K _ (28. 5), 伪 _ (95N) 4.2in geographic coordinates, Ds=1.0 掳, Is=41.5 掳, K _ (34), 伪 95 ~ (3. 8) in plane coordinates. The corresponding pole position is 位 pN 75.9 掳N, 蠁 pN 270.5 掳Etdphe 2.8 掳, dm=4.6 掳. By comparing with the paleomagnetic poles in the Qaidam basin and adjacent areas of the same era, it is shown that the Qaidam block has not experienced a clear rotation movement since the Miocene, and the Altun fault activity has caused the tectonic rotation in the adjacent fault zones such as Subei.
【作者单位】：中国地质科学院地质力学研究所/国土资源部古地磁与古构造重建重点实验室;中国地质科学院地质研究所/大陆动力学国家重点实验室;
【基金】：中国地质调查局基础研究项目(1212011121267,1212011120964) 国家自然科学基金项目(41172177)~~
【分类号】：P542

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